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Paper Title Other Keywords Page
MOPA005 Protection Against Accidental Beam Losses at the LHC beam-losses, proton, superconducting-magnet, dipole 492
  • J. Wenninger, R. Schmidt
    CERN, Geneva
  Protection of the LHC against uncontrolled beam losses is of prime importance due to the very high stored beam energy. For nominal beam intensities, each of the two 7 TeV/c proton beams has a stored energy of 350 MJ threatening to damage accelerator equipment. At injection a number of passive beam absorbers must be correctly positioned and specific procedures have been proposed to ensure safe injection of high intensity. The LHC beam dump block being the only LHC element that can safety absorb the full LHC beam, it is essential that the beams are extracted unto the dump block in case of emergency. The failure time constants extend from 100 microseconds to few seconds depending on the equipment. Failures must be detected at a sufficiently early stage and transmitted to the beam interlock system that triggers the beam dumping system. To ensure safe operation the machine protection system uses a variety of systems to detect such failures. The strategy for protection of the LHC will be illustrated, with emphasis on new developments and studies that aim for an increased redundancy of the protection system.  
MPPT091 Managing Coil Epoxy Vacuum Impregnation Systems at the Manufacturing Floor Level To Achieve Ultimate Properties in State-of-the-Art Magnet Assemblies vacuum, radiation, insertion, induction 4260
  • J.G. Hubrig
    Innovation Services, Inc, Knoxville, Tennessee
  • G.H. Biallas
    Jefferson Lab, Newport News, Virginia
  Liquid epoxy resin impregnation systems remain a state-of-the-art polymer material for vacuum and vacuum/pressure impregnation applications in the manufacture of both advanced and conventional coil winding configurations. Epoxy resins inherent latitude in processing parameters accounts for their continued popularity in engineering applications, but also for the tendency to overlook or misinterpret the requisite processing parameters on the manufacturing floor. Resin system impregnation must be managed in detail in order to achieve device life cycle reliability. This closer look reveals how manufacturing floor level management of material acceptance, handling and storage, pre- and post- impregnation processing and cure can be built into a manufacturing plan to increase manufacturing yield, lower unit cost and ensure optimum life cycle performance of the coil.  
MOPB009 Review of the Production Process of TTF and PITZ Photocathodes cathode, gun, electron, linac 671
  • D. Sertore, P. Michelato, L. Monaco
    INFN/LASA, Segrate (MI)
  • A. Bonucci
    SAES Getters S.p.A., Lainate
  • J.H. Han
    DESY Zeuthen, Zeuthen
  • S. Schreiber
    DESY, Hamburg
  In the present article, the production process of the photocathodes for the TESLA Test Facility (TTF) at DESY Hamburg and the Photo Injector Test Facility at DESY-Zeuthen (PITZ) is reviewed in order to highlight key elements for the final photocathode performances. Since the first photocathode production in 1998, we have continuosly collected relevant paramenters of the cathode plugs and deposition process. These data are now critically analized in view of an optimization of the photocathode performances for the next generation of high brilliance sources.  
TPAP013 The Performance of the New TCDQ System in the LHC Beam Dumping Region simulation, proton, secondary-beams, dumping 1324
  • A. Presland, B. Goddard, W.J.M. Weterings
    CERN, Geneva
  The superconducting quadrupole magnet Q4 in IR6 and other downstream LHC machine elements risk destruction in the event of a beam dump that is not synchronised with the abort gap. In order to protect these elements, a single sided mobile graphite diluter block TCDQ, in combination with a two-sided secondary collimator TCS and an iron shield TCDQM, will be installed in front of Q4. This protection system should also intercept spurious particles in the beam abort gap to prevent quenches from occurring during regular beam aborts, and must also intercept the particles from the secondary halo during low beam lifetime without provoking quenches. The conceptual design of the TCDQ system is briefly presented, with the load conditions and performance criteria. The FLUKA energy deposition simulations are described, and the results discussed in the context of the expected performance levels for LHC operation.  
TPAP027 Deterioration of the Skew Quadrupole Moment in Tevatron Dipoles Over Time quadrupole, coupling, dipole, alignment 1967
  • M.J. Syphers, D.J. Harding
    Fermilab, Batavia, Illinois
  Funding: United States Department of Energy under Contract No. DE-AC02-76CH03000.

During the 20 years since it was first commissioned, the Fermilab Tevatron has developed strong coupling between the two transverse degrees of freedom. A circuit of skew quadrupole magnets is used to correct for coupling and, though capable, its required strength has increased since 1983 by more than an order of magnitude. In more recent years changes to the Tevatron for colliding beams operation have altered the skew quadrupole corrector distribution and strong local coupling become evident, often encumbering routine operation during the present physics run. Detailed magnet measurements were performed on each individual magnet during construction, and in early 2003 it was realized that measurements could be performed on the magnets in situ which could determine coil movements within the iron yoke since the early 1980's. It was discovered that the superconducting coils had become vertically displaced relative to their yokes since their construction. The ensuing systematic skew quadrupole field introduced by this displacement accounts for the required corrector settings and observed beam behavior. An historical account of the events leading to this discovery and progress toward its remedy are presented.

TPAP054 Helium Flow Induced Orbit Jitter at RHIC heavy-ion, injection, quadrupole, emittance 3262
  • C. Montag, P. He, L. Jia, T. Nicoletti, T. Satogata, J. Schmalzle, T. Tallerico
    BNL, Upton, Long Island, New York
  Funding: Work performed under the auspices of the US Department of Energy.

Horizontal beam orbit jitter at frequencies around 10 Hz has been observed at RHIC for several years. The distinct frequencies of this jitter have been found at superconducting low-beta qudrupole triplets around the ring, where they coincide with mechanical modes of the cold masses. Recently, we have identified liquid helium flow as the driving force of these oscillations.

TPAT076 Measurement of the Luminous-Region Profile at the PEP-II IP, and Application to e± Bunch-Length Determination luminosity, simulation, collider, optics 3973
  • B.F. Viaud
    Montreal University, Montreal, Quebec
  • W. Kozanecki
    CEA/DSM/DAPNIA, Gif-sur-Yvette
  • I.V. Narsky
    CALTECH, Pasadena, California
  • C. O'Grady, A. Perazzo
    SLAC, Menlo Park, California
  The three-dimensional luminosity distribution at the interaction point (IP) of the SLAC B-Factory is measured continuously, using e+e- –> e+e- and e+e –> mu+mu- events reconstructed online in the silicon tracker of the BaBar detector. The centroid of the transverse luminosity profile provides a very precise and reliable monitor of medium- and long-term orbit drifts at the IP. The longitudinal centroid is sensitive to variations in the relative RF phase of the colliding beams, both over time and differentially along the bunch train. The measured horizontal r.m.s. width of the distribution is consistent with a sizeable dynamic-beta effect; it is also useful as a benchmark of strong-strong beam-beam simulations. The longitudinal luminosity distribution depends on the e± bunch lengths and vertical IP beta-functions, which can be different in the high- and low-energy rings. Using independent estimates of the beta-functions, we analyze the longitudinal shape of the luminosity distribution in the presence of controlled variations in accelerating RF voltage and/or beam current, to extract separate measurements of the e+ and e- bunch lengths.  
TPAT094 Luminescence Beam Profile Monitor for the RHIC Polarized Hydrogen Jet Polarimeter proton, target, polarization, ion 4293
  • N.P. Luciano, Y. Makdisi, A.N. Nass, P. Thieberger, D. Trbojevic, A. Zelenski
    BNL, Upton, Long Island, New York
  Funding: Work performed under Contract Number DE-AC02-98CH10886 with the auspicies of the US Deparment of Energy.

This is the second polarized proton run in Relativistic Heavy Ion Collider (RHIC) with a new polarized proton jet target used to provide accurate polarization measurements. The interactions between the stored polarized protons with the polarized jet target will produce, in addition to polarization, optical signals due to exited states of Hydrogen or other molecules, ions, or atoms. Additional lenses, optical window, optical analyzer, and the CCD camera are added to the system to allow transfer and detection of optical signals from the interaction chamber. Oxygen or other elements (impurities) could be mixed within the jet target and affect the accuracy of the polarization measurements. It is important to have continuous information of the jet content without affecting the polarization measurements. The optical signals coming from the exited states of molecules, ions, and atoms from the polarized proton beam interaction with the jet will provide that. In addition, the beam profile might be obtained.

TPPE028 In-Situ Electron Cyclotron Resonance (ECR) Plasma Potential Determination Using an Emissive Probe plasma, electron, ion, ion-source 2035
  • F.W. Meyer, Y. Liu
    ORNL, Oak Ridge, Tennessee
  • H.J. You
    Hanyang University, Seoul
  Funding: This research was sponsored by the U.S. DOE under contract No. DE-AC05-00OR22725 with UT-Battelle, LLC. HJY acknowledges support from the Korean Science Education Foundation (KOSEF).

In this paper, real-time, in-situ, plasma potential measurements are reported for an ECR ion source and correlated with extracted beam characteristics. The local real-time plasma potential of the ORNL CAPRICE ECR ion source was measured using an emissive probe, which was inserted perpendicularly from the plasma chamber wall at the mid-plane of the ECR zone between one of the six radial loss cones of the magnetic field structure, where perturbation of the main ECR plasma is expected to be small. Slots machined through the plasma- and puller-electrodes at the plasma chamber wall radius permitted insertion of the probe from the extraction side of the ECR source without perturbation of the coaxial microwave injection. The emissive probe technique permits plasma potential determination independent of plasma conditions and avoids problems related to probe geometry. The probe loop tip was pointed toward the chamber center in a radial plane and was located about 5 mm outside of the ECR zone. Details of the measurements, and a comparison with an external-beam-deceleration-based plasma potential determination will be presented.

TPPT012 High Power Testing of Input Couplers for SuperKEKB vacuum, coupling, electron, positron 1294
  • H. Sakai, T. Abe, T. Kageyama, Y. Takeuchi
    KEK, Ibaraki
  In KEKB, 32 ARES cavities have been successfully operated to stably accelerate high-current electron and positron beams. Currently, each ARES cavity is fed with RF power (frequency = 509 MHz) of about 300 kW through an input coupler, which has a ceramic disk window at the coaxial line section following the doorknob transformer section with a capacitive iris at the rectangular waveguide entrance. For SuperKEKB, which is a challenging project to boost the luminosity frontier beyond 1035 cm-2 s-1, the power capability of the input coupler needs to be upgraded to more than 900 kW, while the design power capability for KEKB is 400 kW. Recently, we have constructed a new test stand in order to simulate the actual operating condition for the input coupler to drive the ARES cavity with the maximum beam loading of 9.4 A expected for the SuperKEKB LER. In this article, the key features of the new test stand are described together with the recent results of high-power tests.  
WPAE001 Helium Distribution for the Superconducting Devices in NSRRC superconducting-magnet, vacuum, storage-ring, radio-frequency 758
  • F.-Z. Hsiao, S. H. Chang, W. S. Chiou, H.C. Li
    NSRRC, Hsinchu
  In NSRRC up to five superconducting magnets and one superconducting cavity will be installed in the storage ring. At current stage two superconducting magnets and one superconducting cavity are kept in cold condition by one 450W helium cryogenic system. The crucial stable cryogenic condition required from the superconducting cavity is hard to achieve due to the join of superconducting magnets. A second cryogenic system dedicated for the superconducting magnets is planned in the next stage. A switch valve box serves the function for the backup of two cryogenic systems for each other and a 100 meter nitrogen-shielding helium transfer line dedicated for the five superconducting magnets are installed at end of the year 2004. This paper presents the helium distribution design of the two cryogenic systems and the commission result of the recent work.  
WPAE005 Status of the Cryogenic System Commissioning at SNS SNS, linac, vacuum, Spallation-Neutron-Source 970
  • F. Casagrande, I.E. Campisi, P.A. Gurd, D.R. Hatfield, M.P. Howell, D. Stout, W.H. Strong
    ORNL, Oak Ridge, Tennessee
  • D. Arenius, J.C. Creel, K. Dixon, V. Ganni, P.K. Knudsen
    Jefferson Lab, Newport News, Virginia
  Funding: SNS is managed by UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S. Department of Energy. SNS is a partnership of six national laboratories: Argonne, Brookhaven, Jefferson, Lawrence Berkeley, Los Alamos and Oak Ridge

The Spallation Neutron Source (SNS) is under construction at Oak Ridge National Laboratory. The cold section of the Linac consists of 81 superconducting radio frequency cavities cooled to 2.1K by a 2400 Watt cryogenic refrigeration system. The major cryogenic system components include warm helium compressors with associated oil removal and gas management, 4.5K cold box, 7000L liquid helium dewar, 2.1K cold box (consisting of 4 stages of cold compressors), gaseous helium storage, helium purification and gas impurity monitoring system, liquid nitrogen storage and the cryogenic distribution transfer line system. The overall system commissioning strategy and status will be presented.

WPAE037 Deformation Monitoring of the Spallation Neutron Source (SNS) Tunnels SNS, survey, alignment, target 2509
  • J.J. Error, D.R. Bruce, J.J. Fazekas, S.A. Helus, J.R. Maines
    ORNL, Oak Ridge, Tennessee
  Funding: SNS is managed by UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S. Department of Energy.

The SNS Project is a 1.4 MW accelerator-based neutron source located at Oak Ridge National Laboratory in Oak Ridge, Tennessee. For shielding purposes, a 17 foot berm of native soil has been constructed on top of the accelerator tunnel system. This backfill has caused ongoing settlement of the tunnels. The settlement has been monitored by the SNS Survey and Alignment Group at regular intervals, in order to discover the patterns of deformation, and to determine when the tunnels will be stable enough for precise alignment of beam line components. The latest monitoring results indicate that the settlement rate has significantly decreased. This paper discusses the techniques and instrumentation of the monitoring surveys, and provides an analysis of the results.

WPAE066 PEP-II Large Power Supplies Rebuild Program at SLAC power-supply, controls, feedback, collider 3685
  • A.C. de Lira, P. Bellomo, J.J. Lipari, F.S. Rafael
    SLAC, Menlo Park, California
  Funding: Work supported by the U.S. Department of Energy under contract number DE-AC02-76SF00515.

At PEP-II, seven large power supplies (LGPS) are used to power quad magnets in the electron-positron collider region. The LGPS ratings range from 72kW to 270kW, and were installed in 1997. They are unipolar off-line switch mode supplies, with a 6 pulse bridge rectifying 480VAC, 3-phase input power to yield 650VDC unregulated. This unregulated 650VDC is then input into one (or two) IGBT H-bridges, which convert the DC into PWM 16 kHz square wave AC. This high frequency AC drives the primary side of a step-down transformer followed by rectifiers and low pass filters. Over the years, these LGPS have presented many problems mainly in their control circuits, making it difficult to troubleshoot and affecting the overall accelerator availability. A redesign/rebuilding program for these power supplies was established under the coordination of the Power Conversion Department at SLAC. During the 2004 accelerator summer shutdown all the control circuits in these supplies were redesigned and replaced. A new PWM control board, programmable logic controller, and touch panel were all installed to improve LGPS reliability, and to make troubleshooting easier. In this paper we present the details of this rebuilding program and results.

WPAE073 3 kA Power Supplies for the Duke OK-5 FEL Wigglers power-supply, feedback, wiggler, storage-ring 3901
  • V. Popov, S.M. Hartman, S. Mikhailov, O. Oakeley, P.W. Wallace, Y.K. Wu
    DU/FEL, Durham, North Carolina
  Funding: U.S. AFOSR MFEL grant F49620-001-0370.

The next generation electromagnetic OK-5/Duke storage ring FEL wigglers require three 3kA/70V power supplies with current stability about 20 ppm and current ripples less than 20ppm in their full operating range. Duke FEL Laboratory acquired three out-of-service thyristor controllable power supplies (Transrex, 5kA/100V) which was built almost 30 years ago. The existing archaic firing circuit, lack of any output voltage filtering and outdated DCCT, would not be able to meet the above requirements.To deliver the desirable high performance with very limited funds, all three T-Rex power supplies have been completely rebuilt in house at DFELL. Modern high stability electronic components and a Danfysik DCCT with a high current stability have been used. New symmetrical firing circuit, efficient passive LC filter and reliable transformer-coupled active filter are used to reduce output current ripples to an appropriate level. At the present time, the first refurbished power supply in operation since August, 2004 with good overall performance. The power supply testing results of this unit will also be presented in this paper.

WPAT034 The CEBAF Separator Cavity Resonance Control System resonance, controls, linac, electron 2339
  • M.J. Wissmann, AA. Guerra, C. Hovater, T. Plawski
    Jefferson Lab, Newport News, Virginia
  Funding: This work supported by the U.S. Department of Energy under contract DE-AC05-84ER40150.

The CEBAF energy upgrade from 6 GeV to 12GeV will increase the range of beam energies available to the experimental halls. RF deflection cavities (separators) are used to direct the electron beam to the three experimental halls. Consequently with the increase in RF separator cavity gradient needed for the higher energies, RF power will also increase requiring the cavities to have active resonance control. At the 6 GeV energy, the cavities are tuned mechanically and then stabilized with Low Conductivity Water (LCW), which is maintained at constant temperature of 95o Fahrenheit. This is no longer feasible and an active resonance control system, that controls both water temperature and flow has been built. The system uses a commercial PLC with embedded PID controls to control water temperature and flow to the cavities. The system allows the operator to remotely adjust temperature/flow and consequently cavity resonance for the full range of beam energies. Ultimately closed loop control will be maintained by monitoring the cavities reflected power. This paper describes this system.

WPAT041 Klystron Linearizer for Use with 1.2 MW 476 MHz Klystrons in PEP-II RF Systems klystron, feedback, impedance, radio-frequency 2660
  • J.D. Fox, T. Mastorides, D. Teytelman, D. Van Winkle, Y.-B. Zhou
    SLAC, Menlo Park, California
  • A. Gallo
    INFN/LNF, Frascati (Roma)
  Funding: Work supported by U.S. Department of Energy contract DE-AC02-76SF00515.

The direct and comb loop feedback around the RF cavities in PEP-II is critical in reducing longitudinal instabilities driven by the cavity impedance, and the non-linear 1 MW klystron is in the signal path for these feedback loops. As a result, the effective small-signal gain of the klystron at 85% saturation reduces the impedance control by factors of 5 to 20 as compared to a linear power amplifier. A klystron linearizer circuit has been developed which operates in series with the power amplifier and acts to equalize the small and large signal gains through the combination. The technique must implement a 1 MHz linear control bandwidth over roughly 15 dB of RF signal level variation. The dynamics of this system is operating point dependent, and the channel must have dynamic gain compensation to keep the linearity compensation loop stable over changes in operating point. The design of this non-linear signal processing channel (incorporating RF and DSP techniques) and measured results from full-power klystron testing are presented.

WPAT058 Operational Experience with the Spallation Neutron Source High Power Protection Module SNS, linac, klystron, Spallation-Neutron-Source 3411
  • M.T. Crofford, M. Champion, K.-U. Kasemir, H. Ma, M.F. Piller
    ORNL, Oak Ridge, Tennessee
  The Spallation Neutron Source (SNS) High Power Protection Module provides protection for the High Power RF Klystron and Distribution System and interfaces with the Low-Level Radio-Frequency (LLRF) Field Control Module (FCM). The fault detection logic is implemented in a single FPGA allowing modifications and upgrades to the logic as we gain operational experience with the LINAC RF systems. This paper describes the integration and upgrade issues we have encountered during the initial operations of the SNS systems.  
WPAT059 High Power RF Test Facility at the SNS SNS, klystron, vacuum, linac 3450
  • Y.W. Kang, D.E. Anderson, I.E. Campisi, M. Champion, M.T. Crofford, R.E. Fuja, P.A. Gurd, S. Hasan, K.-U. Kasemir, M.P. McCarthy, D. Stout, J.Y. Tang, A.V. Vassioutchenko, M. Wezensky
    ORNL, Oak Ridge, Tennessee
  • G.K. Davis, M. A. Drury, T. Powers, M. Stirbet
    Jefferson Lab, Newport News, Virginia
  RF Test Facility has been completed in the SNS project at ORNL to support test and conditioning operation of RF subsystems and components. The system consists of two transmitters for two klystrons powered by a common high voltage pulsed converter modulator that can provide power to two independent RF systems. The waveguides are configured with WR2100 and WR1150 sizes for presently used frequencies: 402.5 MHz and 805 MHz. Both 402.5 MHz and 805 MHz systems have circulator protected klystrons that can be powered by the modulator capable of delivering 11 MW peak and 1 MW average power. The facility has been equipped with computer control for various RF processing and complete dual frequency operation. More than forty 805 MHz fundamental power couplers for the SNS superconducting linac (SCL) cavitites have been RF conditioned in this facility. The facility provides more than 1000 ft2 floor area for various test setups. The facility also has a shielded cave area that can support high power tests of normal conducting and superconducting accelerating cavities and components.

SNS is managed by UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S. Department of Energy. SNS is a partnership of six national laboratories: Argonne, Brookhaven, Jefferson, Lawrence Berkeley, Los Alamos, and Oak Ridge.

WPAT069 Development of a Solid State RF Amplifier in the kW Regime for Application with Low Beta Superconducting RF Cavities simulation, ion, booster, insertion
  • C. Piel
    ACCEL, Bergisch Gladbach
  • B. A. Aminov, A. Borisov, S. K. Kolesov, H. Piel
    CRE, Wuppertal
  Projects based on the use of low beta superconducting cavities for ions are under operation or development at several labs worldwide. Often these cavities are individually driven by RF power sources in the kW regime. For an ongoing project a modular 2 kW, 176 MHz unconditionally stable RF amplifier for CW and pulsed operation was designed, built, and tested. Extended thermal analysis was used to develop a water cooling system in order to optimize the performance of the power transistors and other thermally loaded components. The paper will outline the design concept of the amplifier and present first results on the test of the amplifier with a superconducting cavity.  
WPAT074 In Depth Diagnostics for RF System Operation in the PEP-II B Factory diagnostics, klystron, feedback, beam-losses 3931
  • D. Van Winkle, J.D. Fox, D. Teytelman
    SLAC, Menlo Park, California
  Funding: Work supported by U.S. Department of Energy contract DE-AC02-76SF00515.

The PEP-II RF systems incorporate numerous feedback loops in the low-level processing for impedance control and operating point regulation. The interaction of the multiple loops with the beam is complicated, and the systems incorporate online diagnostic tools to configure the feedback loops as well as to record fault files in the case of an RF abort. Rapid and consistent analysis of the RF-related beam aborts and other failures is critical to the reliable operation of the B-Factory, especially at the recently achieved high beam currents. Procedures and algorithms used to extract diagnostic information from time domain fault files are presented and illustrated via example interpretations of PEP-II fault file data. Example faults presented will highlight the subtle interpretation required to determine to root cause. Some such examples are: abort kicker firing asynchronously, klystron and cavity arcs, beam loss leading to longitudinal instability, tuner read back jumps and poorly configured low-level RF feedback loop.

RPAE043 Beam Position Monitor for Undulator by Using SR Monitor Technique undulator, radiation, focusing, photon 2789
  • T. Mitsuhashi, M.T. Tadano
    KEK, Ibaraki
  A beam position monitor for the undulator by using the optical SR monitor technique has been tested in the Photon Factory. A visible SR in far tail of the undurater spectrum is extracted by a water-cooled beryllium mirror. The extraction mirror has a hole in the center for passing through the central peak of the undulator radiation which has an opening angle of 1/gamma. Extracted visible light in large opening angle has exactly same optical axis of the undulator radiation, because of it’s a far tail of the spectrum of same radiation. We applied focusing system to observe the beam position in the undulator through the optical image of beam. The results show us this method is applicable to monitor a position of beam in the undulator, and gap change of undulator has no effect of beam position monitoring. We can easily measure the angle of visible ray, this method is applicable not only beam position monitor but also monitoring the angular deviation of undulator radiation.  
RPAE060 Simulation and Automation of the EEBI Test at ALS target, simulation, vacuum, synchrotron 3485
  • H. Nishimura, W.E. Byrne
    LBNL, Berkeley, California
  Funding: Work supported by the U.S. Department of Energy under Contract No. DE-AC03-76SF00098.

The Errant Electron Beam Interlock (EEBI) is a system that protects the vacuum chamber of the Advanced Light Source (ALS) from synchrotron light damage should the orbit, through a superconducting bend magnet (superbend), become distorted. The EEBI system monitors the vertical beam position on two BPMs, one upstream and the other downstream, of the superbend and dumps the stored beam if the orbit exceeds preset limits in either offset or angle. Discussed are the modeling studies carried out to determine how to create a large vertical bump, both for performing the test and implementing the automated test software.

RPAE080 Diagnostic Systems Plan for the Advanced Light Source Top-Off Upgrade injection, kicker, betatron, diagnostics 4066
  • T. Scarvie, W. Barry, M.J. Chin, D. Robin, F. Sannibale, C. Steier
    LBNL, Berkeley, California
  Funding: This work was supported by the Director, Office of Energy Research, Office of Basic Energy Sciences, Materials Science Division, of the U.S. Department of Energy under Contract No. DE-AC03-76SF00098.

The Advanced Light Source (ALS) will soon be upgraded to enable top-off operation,* in which electrons are quasi-continuously injected to produce constant stored beam current. We will upgrade our injector from 1.5GeV to full-energy 1.9GeV, and top-off operation will also require more precise injector beam characterization and control than we are capable of using our current diagnostics system. Therefore, a diagnostics upgrade will be crucial for the success of top-off, and our plan for it is described in this paper. Among the improvements will be the integration of all existing beam current monitors along the accelerator chain into an injection efficiency monitoring application. New booster ring diagnostics will include a tune kick and monitoring system, updated beam position monitor electronics, and a new scraper. Two new synchrotron light monitors and a beam stop will be added to the booster-to-storage ring transfer line, and a dedicated bunch purity monitoring system will be installed in the storage ring. Together, these important diagnostic upgrades will enable smooth commissioning of the full energy injector and a quick transition to high quality top-off operation at the ALS.

*Please see the ALS Top-off Upgrade presentation at this conference.

RPAP013 Characteristic Experimentations of Degrader and Scatterer at MC-50 Cyclotron proton, cyclotron, target, simulation 1356
  • S.-K. Lee, B.H. Choi, K. R. Kim, LHR. Lee, B.-S. Park
    KAERI, Daejon
  Funding: This work is a part of the "Proton Engineering Frontier Project" which is sponsored by the Ministry of Science and Technology of Korea under "21C Frontier R&D Program."

Building proton beam user facilities, especially deciding beam energy level, depends on the attached proton accelerator and users' needs. To adjust beam energy level, two methods are generally used. One is to directly adjust the beam in the accelerator. The other is to adjust beam energy after extracting from the accelerator. Degrader/Scatterer System has been installed in the MC-50 Cyclotron to adjust energy level of the beam used for various application fields. Its degrader and scatterer are made of Al foils and Au foils, respectively. Al thickness are 2, 1, 0.5, 0.3, 0.2, 0.1, 0.05, 0.03, 0.02, 0.01mm and Au thickness are 0.2, 0.1, 0.05, 0.03, 0.02, 0.01mm, respectively. In this study, suitable beam condition was adjusted through overlapping Al/Au foils of various thickness through simulation results. After that, LET(Linear Energy Transfer) value was indirectly acquired by measuring the bragg peak of the external beam through PMMA plastic Phantom and profile was measured by film dosimetry.

RPAP046 Real-Time Beam Loss Monitor Display Using FPGA Technology beam-losses, synchrotron, background, linac 2914
  • M.R.W. North, A.H. Kershaw
    CCLRC/RAL/ISIS, Chilton, Didcot, Oxon
  This paper outlines the design of a Real-time Beam Loss Monitor Display for the ISIS Synchrotron based at Rutherford Appleton Laboratory (Oxon, UK). Beam loss is monitored using 39 argon filled ionisation chambers positioned around the synchrotron, the levels of which are sampled four times in each cycle. The new BLM display acquires the signals and displays four histograms, each relating to an individual sample period; the data acquisition and signal processing required to build the display fields are completed within each machine cycle (50 Hz). Attributes of the new system include setting limits for individual monitors; displaying over-limit detection, and freezing the display field when a beam trip has occurred. The design is based around a reconfigurable Field Programmable Gate Array, interfacing to a desktop monitor via the VGA standard. Results gained using simulated monitor signals have proven the system.  
RPAP047 DAQ System of BPM and BCT for the BEPCII Linac linac, positron, pick-up, electron 2980
  • J. Cao, Q. Ye
    IHEP Beijing, Beijing
  Following the BEPCII upgrade, total about 19 BPM and 12 BCT have been newly installed in the BEPCII Linac. Also, a set of distributed control system based on EPICS architecture has been built, and the BPM and BCT system are merged into the new control system for the data acquisition. In order to reduce the effects of RF noise, a special gated integrator was used to measure the beam current. In this paper we will describe the DAQ system of BPM and BCT including calibrations in detail.  
RPAT002 Production of Inorganic Thin Scintillating Films for Ion Beam Monitoring Devices proton, ion, diagnostics, background 808
  • M. Re, G.A.P. Cirrone, L. Cosentino, G. Cuttone, P. Finocchiaro, P.A. Lojacono
    INFN/LNS, Catania
  • A. Hermanne, H. Thienpont, J. Van Erps, M. Vervaeke, B. Volckaerts, P. Vynck
    VUB, Brussels
  • Y.J. Ma
    CIAE, Beijing
  In this work we present the development of beam monitoring devices consisting of thin CsI(Tl) films deposited on Aluminium support layers. The light emitted by the scintillating layer during the beam irradiation is measured by a CCD-camera. In a first prototype a thin Aluminium support layer of 6 micron allows the ion beam to easily pass through without significant energy loss and scattering effects. Therefore it turns out to be a non-destructive monitoring device to characterize on-line beam shape and beam position without interfering with the rest of the irradiation process. A second device consists of an Aluminium support layer which is thick enough to completely stop the impinging ions allowing to monitor at the same time the beam profile and the beam current intensity. Some samples have been coated by a 100 Å protective layer to prevent the film damage by atmosphere exposition. In this contribution we present our experimental results obtained by irradiating the samples with proton beams at 8.3 and 62 MeV. We also propose some innovative applications of these beam monitoring devices in different nuclear sectors such as cancer proton therapy and high intensity beam accelerators.  
RPAT008 Prototype Digital Beam Position and Phase Monitor for the 100-MeV Proton Linac of PEFP proton, linac, instrumentation, SNS 1120
  • I.H. Yu, D.T. Kim, S.-C. Kim, I.-S. Park, S.J. Park
    PAL, Pohang, Kyungbuk
  • Y.-S. Cho
    KAERI, Daejon
  Funding: Work supported by the PEFP (Proton Engineering Frontier Project), Korea.

The PEFP (Proton Engineering Frontier Project) at the KAERI (Korea Atomic Energy Research Institute) is building a high-power proton linear accelerator aiming to generate 100-MeV proton beams with 20-mA peak current (pulse width and max. repetition rate of 1 ms and 120 Hz respectively). We are developing a prototype digital BPPM (Beam Position and Phase Monitor) for the PEFP linac utilizing the digital technology with field programmable gate array (FPGA). The RF input signals are down converted to 10 MHz and sampled at 40 MHz with 14-bit ADC to produce I and Q data streams. The system is designed to provide a position and phase resolution of 0.1% and 0.1? RMS respectively. The fast digital processing is networked to the EPICS-based control system with an embedded processor (Blackfin). In this paper, the detailed description of the prototype digital beam position and phase monitor will be described with the performance test results.

RPAT054 Beam Position Monitor at the PLS BTL linac, electron, pick-up, injection 3289
  • S.-C. Kim, M.-H. Chun, Y.J. Han, J.Y. Huang, D.T. Kim, W.W. Lee
    PAL, Pohang, Kyungbuk
  Funding: Work supported by the Ministry of Science and Technology, Korea.

Electron Linac at the Pohnag Accelerator Laboratory (PAL) has been operated continuously as the full energy injector for storage ring. Linac and storage ring energy has been 2.0 GeV since Dec. 1994, and 2.5 GeV since Oct. 2002. In Aug. 2004, thirteen BPMs are newly installed at BTL(Beam Transport Line) for beam trajectory measurement and feedback. These BPMs consist of 100mm strip-line electrodes in 150mm long chamber, and 500MHz log-ratio signal processing circuits. BPM data acquisition system is developed as EPICS IOC using NI S-series data acquisition board and NI LabView 7.1. BTL BPMs will be used for optic correction and beam energy feedback for PLS beam injection. This paper describes on design, test results, installation and data acquisition system of the PLS BTL BPM.

RPAT061 New Electron Beam Position Monitoring and Feedback System Upgrades for the Synchrotron Radiation Source at Daresbury Laboratory feedback, storage-ring, electron, pick-up 3538
  • R.J. Smith, M. Dufau, B.G. Martlew
    CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire
  • G. Cox
    CCLRC/DL, Daresbury, Warrington, Cheshire
  Funding: ASTeC Department, CCLRC Daresbury Laboratory.

The installation of a new APPLE/II undulator with user controlled polarisation has necessitated the upgrade of the Electron Beam Position Monitoring (EBPM) detector electronics and position feedback systems. The upgraded installation will utilise commercially available multiplexed detection electronics, coupled with a two phase control system interface replacement. Phase one involves the replacement of the existing G-64 based read-back system with direct analogue connections to the VME beam steering and Feedback system. This allows existing monitoring and feedback software to work with improved update rates (~ 1Hz -> ~ 8Hz). Phase two will see the installation of new high-performance control system front ends and will allow real-time monitoring at up to 100Hz and provide snapshots with resolution of 1-10 KHz.

RPAT062 Design and Operation of a Radiative Bhabha Luminosity Monitor for CESR-c luminosity, photon, vacuum, positron 3564
  • M.A. Palmer, D. L. Rubin, J.C. Smith
    Cornell University, Laboratory for Elementary-Particle Physics, Ithaca, New York
  • M. Cravey, J. Napalitano
    RPI, Troy, New York
  • V. Crede
    Cornell University, Department of Physics, Ithaca, New York
  • K.L. Dooley
    Vassar, Poughkeepsie, New York
  • H. Vogel
    CMU, Pittsburgh, Pennsylvania
  Funding: Work supported by the National Science Foundation.

The CLEO-c experiment at the Cornell Electron Storage Ring (CESR) is presently embarking on a multi-year exploration of charm and QCD physics in the 3-5 GeV center-of-mass energy range. In order to facilitate rapid optimization of machine parameters over this energy range, a luminosity monitor based on the measurement of radiative-bhabha photons coming from the CLEO-c interaction point (IP) has been designed and installed in the CESR ring. Key design criteria of the device include: better than 1% statistical measurements of the luminosity with a 1 Hz update rate over the full range of CESR-c operating conditions; bunch-by-bunch measurement capability; a large horizontal aperture to enable measurements under conditions ranging from single-bunch head-on collisions to multi-bunch collisions with a horizontal crossing angle of up to 4~mrad; and, a segmented readout to provide direct information on beam characteristics at the IP. We review the design and performance of this device and discuss its application to machine tuning and performance studies.

RPAT071 Digital Beam Position Monitor for the Happex Experiment instrumentation, controls, linac, survey 3841
  • S.R. Kauffman, H. Dong, A. Freyberger, L. Kaufman, J. Musson
    Jefferson Lab, Newport News, Virginia
  Funding: This work was supported by DOE contract No. DE-AC05-84ER40150.

The proposed HAPPEX experiment at CEBAF employs a three cavity monitor system for high-precision (1 mm), high-bandwidth (100 kHz) position measurements. This is performed using a cavity triplet consisting of two TM110-mode cavities (one each for X and Y planes) combined with a conventional TM-010-mode cavity for a phase and magnitude reference. Traditional systems have used the TM010 cavity output to directly down convert the BPM cavity signals to base band. The Multi-channel HAPPEX digital receiver simultaneously I/Q samples each cavity and extracts position using a CORDIC algorithm. The hardware design consists of a digital receiver daughter board and digital processor motherboard that resides in a VXI crate. The daughter board down converts 1.497 GHz signals from the TM010 cavity and X and Y signals from the TM110 cavities to 4 MHz, and extracts the quadrature digital signals. The motherboard processes this data and computes beam intensity and X-Y positions with a resolution of one mm, 100 kHz output bandwidth, and overall latency of ten microseconds. The results are available in both analog and digital format.

RPAT077 Beam Test Proposal of an ODR Beam Size Monitor at the SLAC FFTB target, radiation, photon, optics 4015
  • Y. Fukui, D. Cline, F. Zhou
    UCLA, Los Angeles, California
  • A. Aryshev, V. Karataev, T. Muto, M. Tobiyama, J.U. Urakawa
    KEK, Ibaraki
  • P.R. Bolton, M.C. Ross
    SLAC, Menlo Park, California
  • R. Hamatsu
    TMU, Hatioji-shi,Tokyo
  • G.A. Naumenko, A. Potylitsyn, A. Sharafutdinov
    Tomsk Polytechnic University, Physical-Technical Department, Tomsk
  We design a single bunch transverse beam size monitor which will be tested to measure the 29 GeV electron/positron beam at the SLAC FFTB beam line.The beam size monitor uses a CCD camera to make images of the interference pattern of the optical diffraction radiation from conductive slit target which are placed close to the beam path. In this method, destruction of the accelerated electron/positron beam bunches due to the beam size monitoring is negligible, which is vital to the operation of the Linear Collider project. A dis-phased conductive slit target and a lens system allow us to recover the sensitivity of the transverse beam size with a small photon yield ratio at the valley to that at the peak due to the large gamma*λ, and with the near field effect due to the large λ*gamma**2. A solution for non-negligible divergence at the SLAC FFTB is also discussed.  
RPAT090 The Study of New Signal Processing Technique in Photon Beam Position Monitors photon, synchrotron, synchrotron-radiation, radiation 4239
  • S.F. Lin, H. Gao, P. Lu, B. Sun, J. Wang
    USTC/NSRL, Hefei, Anhui
  A log-ratio signal processing technique in photon beam position monitors (PBPM) was presented in this paper. The main performances (e.g. sensitivity, position offset and linearity range) of split PBPM and a pair of wires PBPM were analyzed , and the result of the measurement fit well with the theory. An inexpensive logarithmic amplifier chip which can measure photon currents from 0.1nA to 3.5mA was used in electronic circuits. The logarithmic ratio of the signal amplitudes from the PBPM provides a real-time analog signal that has wider linearity range and higher bandwidth than signal processing technique.

Supported by Natural Science Foundation of China (10275062) and CAS Knowledge Innovation Project (KY4206).

RPAT094 Femtosecond Synchronisation of Ultrashort Pulse Lasers to a Microwave RF Clock laser, linac, resonance, feedback 4299
  • A. Winter
    Uni HH, Hamburg
  • N. Ignashin, A. Simonov, S. Sytov
    IHEP Protvino, Protvino, Moscow Region
  • E.-A. Knabbe, S. Simrock, B. Steffen
    DESY, Hamburg
  A precise synchronization between the laser repetition rate and the linac-RF is mandatory for electro-optic sampling or pump-probe experiments. The level of stability is usually determined by measuring of the spectral noise power density of the feedback signal when the system is locked. However, an independent measurement is needed to confirm this. In this paper, we present an approach exploiting electronic techniques to synchronize a TiSa laser to the RF of the DESY VUVFEL with sub-50 fs stability. The remaining time jitter is measured by an RF monitoring system independent of the locking PLL.  
RPAT100 Radiation-Hard Beam Position Detector for Use in the Accelerator Dump Lines target, electron, radiation, radio-frequency 4341
  • P. Degtiarenko, D.W. Dotson, V.P. Popov
    Jefferson Lab, Newport News, Virginia
  Funding: This work supported by the U.S. Department of Energy under contract DE-AC05-84ER40150

The new proposed method of beam position measurement is particularly suitable for monitoring high energy, and high power accelerated beams of charged particles in the vicinity of power beam dumps. Generally, the beam quality in those areas is very poor, and any equipment positioned there must be extremely resistant to radiation damage. We have found that a plate made of Chemical Vapor Deposition (CVD) Silicon Carbide (SiC) has a set of physical properties that make it suitable for such an application. CVD SiC material is a chemically inert, extremely radiation-hard, thermo-resistive semiconductor capable of withstanding working temperatures up to 2000 degrees Kelvin. It has good thermal conductivity comparable to that of Aluminum, which makes it possible to use it in high-current particle beams. High electrical resistivity of the material, and its semiconductor properties allow characterization of the position of a particle beam crossing such a plate by measuring balance of electrical currents at the plate ends. The design of a test device, and first results are presented in the report.

RPPE015 Diagnostics and Protection Control for IREN Linac Test Facility diagnostics, linac, electron, instrumentation
  • V.N. Zamriy
    JINR, Dubna, Moscow Region
  The diagnostic and protection control systems for the full-scale test facility of the linear electron accelerator are constructed according to the project on pulsed neutron source IREN. Combined control schemes of timed diagnostics of a duty cycle and real-time protection control are created for the linac test facility. Applicability of the diagnostics systems of cycle parameters and deviations of a status for control of the mode of protection is shown. Multichannel control modules of the protection system have been developed for logging and diagnostics of a status change, the alarms and control of a mode of operation. The applied multiway controllers for duty protection with fast locking of cycles of the IREN linac are presented.  
RPPE022 Machine Protection System for Concurrent Operation of RHIC and BLIP proton, controls, linac, radiation 1754
  • M. Wilinski, S. Bellavia, J. Glenn, L.F. Mausner, K.L. Unger
    BNL, Upton, Long Island, New York
  Funding: Work performed under Contract Number DE-AC02-98CH10886 with the auspices of the U.S. Department of Energy.

The Brookhaven 200 MeV linac is a multipurpose machine used to inject low intensity polarized protons ultimately ending up in RHIC as well as to inject high intensity protons to BLIP, a medical isotope production facility. If high intensity protons were injected to RHIC by mistake, administrative radiation limits could be exceeded or sensitive electronics could be damaged. In the past, the changeover from polarized proton to high intensity proton operation has been a lengthy process, thereby never allowing the two programs to run simultaneously. To remedy this situation and allow for concurrent operation of RHIC and BLIP, an active interlock system has been designed to monitor current levels in the AGS using two current transformers with fail safe circuitry and associated electronics to inhibit beam to RHIC if high intensity is detected.

RPPE062 The Use of Integrated Electronic Data Capture and Analysis for Accelerator Construction and Commissioning: Pansophy from the SNS Towards the ILC SNS, linac, site, feedback 3556
  • J.P. Ozelis, V. Bookwalter, B.D. Madre, C.E. Reece
    Jefferson Lab, Newport News, Virginia
  Funding: Work supported by U.S. Department of Energy under contract DE-AC05-84ER40150.

Jefferson Lab has extensively used a proprietary web-based system (Pansophy) that integrates commercial database, data analysis, document archiving and retrieval, and user interface software, as a coherent knowledge management product during the construction of the cryomodules for the SNS Superconducting Linac, providing elements of process and procedure control, data capture and review, and data mining and analysis. With near real-time and potentially global access to production data, process monitoring and performance analyses could be pursued in a timely manner, providing crucial feedback. The extensibility, portability, and accessibility of Pansophy via universally available software components provide the essential features needed in any information and project management system capable of meeting the needs of future accelerator construction efforts, requiring an unprecedented level of regional and international coordination and collaboration, to which Pansophy is well suited.

RPPE065 Beam Loss Ion Chamber System Upgrade for Experimental Halls ion, radiation, target, beam-losses 3650
  • D.W. Dotson, D.J. Seidman
    Jefferson Lab, Newport News, Virginia
  Funding: Work supported by: U.S. DOE Contract No DE-AC05-84ER4015.

The Beam loss Ion Chamber System (BLICS) was developed to protect Jefferson Labs transport lines, targets and beam dumps from a catastrophic "burn through." Range changes and testing was accomplished manually requiring the experiment to be shut down. The new upgraded system is based around an "off the shelf" Programmable Logic Controller located in a single controll box supporting up to ten individual detectors. All functions that formerly required an entry into the experimental hall and manual adjustment can be accomplished from the Machine Control Center (MCC). A further innovation was the addition of a High Voltage "Brick" at the detector location. A single cable supplies the required voltage for the Brick and a return line for the ion chamber signal. The read back screens display range, trip point, and accumulated dose for each location. The new system is very cost effective and significantly reduces the amount of lost experimental time.

RPPE068 A Magnetostrictive Tuning System for Particle Accelerators vacuum, radio-frequency, background, synchrotron 3762
  • C.-Y. Tai, J. Cormier, W. J. Espinola, Z. Han, C.H. Joshi, A. Mavanur, L.M. Racz
    Energen, Inc., Lowell, Massachusetts
  • E. Daly, G.K. Davis
    Jefferson Lab, Newport News, Virginia
  • K.W. Shepard
    ANL, Argonne, Illinois
  Funding: This work is supported by DOE SBIR Program DE-FG02-03ER83648.

Energen, Inc. has designed, built, and demonstrated several fast and slow tuners based on its magnetostrictive actuators and stepper motor. These tuners are designed for Superconducting Radio Frequency (SRF) cavities, which are important structures in particle accelerators that support a wide spectrum of disciplines, including nuclear and high-energy physics and free electron lasers (FEL). In the past two years, Energen’s work has focused on magnetostrictive fast tuners for microphonics and Lorentz detuning compensation on elliptical-cell and spoke-loaded cavities, including the capability for real-time closed-loop control. These tuners were custom designed to meet specific requirements, which included a few to 100 micron stroke range, hundreds to kilohertz operation frequency, and cryogenic temperature operation in vacuum or liquid helium. These tuners have been tested in house and at different laboratories, such as DESY, Argonne National Lab, and Jefferson Lab. Some recent results are presented in this paper.

RPPE072 The Improvement and Data Acquisition Systems on Electrical Systems and Grounding Networks in NSRRC injection, septum, storage-ring, electromagnetic-fields 3868
  • Y.-H. Liu, J.-C. Chang, J.-R. Chen, Y. Lin, Z.-D. Tsai
    NSRRC, Hsinchu
  Funding: NSRRC.

The purpose of this paper is to declare the improvement on electrical and grounding systems in NSRRC. In electrical power system, an Automated Voltage Regulator (AVR) was established to RF system in 2003. The variation of voltage supply from Taiwan Power Company (TPC) is reduced from 3% to 0.2% through the AVR system. And a Supervisory Control and Data Acquisition (SCADA) system was also setup to monitoring the electrical power conditions in each power station. After the high precision grounding systems were constructed in 2004, the stability of beam line was raised. For comprehending the grounding current and noise control, a grounding monitoring system with 32 channels was built in the storage ring. The grounding currents of 4 kickers, one septum and grounding bus are on-line acquisition. Two Electromagnetic Field (EMF) apparatuses were also installed to collect electrical and magnetic fields in the R1 section. It was observed that the electromagnetic field was correlated to grounding currents in certain locations. Injection effects were clearly found in most monitored data. Some improvement works, including expansion of the grounding monitoring system composing analytical software will integrate in the next step.

RPPE077 A Complete System for Operation of a Superconducting Magnet power-supply, wiggler, superconducting-magnet, controls 4003
  • G.W. Codner, M.W. Comfort, D.M. Sabol, T.F. VanDerMark, D.W. Widger, R.J. Yaeger
    CESR-LEPP, Ithaca, New York
  Funding: National Science Foundation.

A complete system for operating, protecting and monitoring a superconducting magnet is described. This system is used in CESR (Cornell Electron Storage Ring) at Cornell University's Laboratory for Elementary Particle Physics (LEPP) for the CESR superconducting wigglers, part of the accelerator upgrade in pursuit of the CESR charm physics program known as CESR-c.

ROPA004 CEBAF Control Room Renovation controls, plasma, linac, synchrotron 378
  • M. Spata, A. Cuffe, H. Fanning, T.C.O. Oren
    Jefferson Lab, Newport News, Virginia
  The Machine Control Center at Jefferson Lab's Continuous Electron Beam Accelerator Facility was initially constructed in the early 1990s and based on proven technology of that era. Through our experience over the last 15 years and in our planning for the facilities 12 GeV upgrade we reevaluated the control room environment to capitalize on emerging visualization and display technologies and improve on workflow processes and ergonomic attributes. This effort also sets the foundation for the redevelopment of the accelerator's control system to deliver high reliability performance with improvements in beam specifications management and information flow. The complete renovation was performed over a three-week period with no interruption to beam operations. We present the results of this effort.  
FPAE043 Transverse Tuning Scheme for J-PARC Linac linac, quadrupole, coupling, emittance 2750
  • M. Ikegami, Z. Igarashi, S. Lee
    KEK, Ibaraki
  • H. Akikawa, K. Hasegawa, Y. Kondo, T. Ohkawa
    JAERI, Ibaraki-ken
  • H. Ao, S. Sato, T. Tomisawa, A. Ueno
    JAERI/LINAC, Ibaraki-ken
  In a high-intensity linac, precise transverse matching is essential for beam halo mitigation. In this paper, we present the supposed transverse tuning scheme for J-PARC linac and the planned beam diagnostic layout for it. Relevantly, we briefly touch upon the tuning scenario for the arc section and the transverse halo collimator system which are located between the linac and the succeeding ring.  
FPAE049 Development and Implementation of ?T Procedure for the SNS Linac linac, SNS, simulation, beam-loading 3064
  • A. Feschenko, S. Bragin, Y. Kiselev, L.V. Kravchuk, O. Volodkevich
    RAS/INR, Moscow
  • A.V. Aleksandrov, J. Galambos, S. Henderson, A.P. Shishlo
    ORNL, Oak Ridge, Tennessee
  Funding: SNS is managed by UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S. Department of Energy.

The ?t procedure is a time of flight technique for setting the phases and amplitudes of accelerating fields in a multi-cavity linac. It was initially proposed and developed for the LAMPF linac in the early seventies and since then has been used in several accelerators. The SNS linac includes four CCL modules (Side Coupled Structure) operating at 805 MHz for the energy range from 86.8 MeV up to 185.6 MeV. The ?t procedure has been implemented for the SNS CCL linac and was used for its initial beam commissioning. Brief theory of the procedure, the results of the design parameter calculations and the experimental results of phase and amplitude setpoints are presented and discussed.

FPAT011 Fast Automated Decoupling at RHIC coupling, quadrupole, resonance, instrumentation 1254
  • J. Beebe-Wang
    BNL, Upton, Long Island, New York
  Funding: Work performed under the auspices of the U.S. DOE.

Coupling correction is essential for the operational performance of RHIC. The independence of the transverse degrees of freedom makes diagnostics and tune control easier, and it is advantageous to operate an accelerator close to the coupling resonance to minimize nearby nonlinear sidebands. An automated decoupling application has been developed at RHIC for coupling correction during routine operations. The application decouples RHIC globally by minimizing the tune separation through finding the optimal settings of two orthogonal skew quadrupole families. The program provides options of automatic, semi-automatic and manual decoupling operations. It accesses tune information from all RHIC tune measurement systems: the PLL (Phase Lock Loop), the high frequency Schottky system, and the tune meter. It also supplies tune and skew quadrupole scans, finding the minimum tune separation, display the real time results and interface with the RHIC control system. We summarize the capabilities of the decoupling application, and discuss the operational protections incorporated in the program. We also report the decoupling performances with the application during the RHIC 2005 run.

FPAT038 Electromagnetic Simulations of Dielectric Wall Accelerator Structures for Electron Beam Acceleration simulation, impedance, acceleration, coupling 2550
  • S.D. Nelson, B.R. Poole
    LLNL, Livermore, California
  Funding: This work was performed under the auspices of the U.S. Department of Energy by the University of California, Lawrence Livermore National Laboratory under Contract No. W-7405-Eng-48.

Dielectric Wall Accelerator (DWA) technology incorporates the energy storage mechanism, the switching mechanism, and the acceleration mechanism for electron beams. Electromagnetic simulations of DWA structures includes these effects and also details of the switch configuration and how that switch time affects the electric field pulse which accelerates the particle beam. DWA structures include both bi-linear and bi-spiral configurations with field gradients on the order of 20MV/m and the simulations include the effects of the beampipe, the beampipe walls, the DWA High Gradient Insulator (HGI) insulating stack, wakefield impedance calculations, and test particle trajectories with low emittance gain. Design trade-offs include the transmission line impedance (typically a few ohms), equilibration ring optimization, driving switch inductances, and a layer-to-layer coupling analysis and its affect on the pulse rise time.

FPAT045 Upgrade of the ESRF Vacuum Control System vacuum, storage-ring, radiation, diagnostics 2857
  • D. Schmied, E. Burtin, P. Guerin, M. Hahn, R. Kersevan
    ESRF, Grenoble
  The temperature acquisition as well as the whole vacuum control system of the electron storage ring of the ESRF is in operation since more than ten years now. Apart from difficulties to have appropriate support for the old systems we start facing problems of aging and obsolescence. We have been reviewing our philosophy of data acquisition and remote control in order to update our systems with state of the art technology, taking into account our operational experience. We have started installing shielded “intelligent” devices inside the storage ring tunnel taking benefit from the availability of ethernet connections. Like this we can take advantage of the latest developments linked to these technologies, such as OPC Server, Webpage instrument control, and more.  
FPAT047 Control System of 3 GeV Rapid Cycling Synchrotron at J-PARC simulation, linac, power-supply, beam-losses 2968
  • H. Takahashi, Y. Kato, M. Kawase, H. Sako
    JAERI/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
  • Y. Ito
    Total Saport System Corp., Naka-gun, Ibaraki
  • H. Sakaki
    JAERI/LINAC, Ibaraki-ken
  • M. Sugimoto
    Mitsubishi Electric Control Software Corp, Kobe
  • H. Yoshikawa
    JAERI, Ibaraki-ken
  Funding: Japan Society for the Promotion of Science (JSPS).

Since the 3GeV RCS produces huge beam power of 1 MW, extreme cares must be taken to design the control system in order to minimize radiation due to beam loss. Another complexity appears in the control system, because each beam bunch of 25 Hz is required to be injected either into the MLF* or into the 50GeV MR.** Therefore, each bunch of 25 Hz must be operated separately, and the data acquisition system must collect synchronized data within each pulse. To achieve these goals, a control system via reflective memory and wave endless recorders has been developed. EPICS is adopted in the control system. Since the number of devices is huge, the management of EPICS records and their configurations require huge amount of time and man power. To reduce this work significantly, a RDB*** for static machine information has been developed. This RDB stores (1) EPICS related information of devices, interfaces, and IOC's**** with a capability to generate EPICS records automatically, and (2) machine geometrical information with a capability to generate lattice files for various simulation applications. The status of the control system focusing on the data acquisition system and the RDB will be presented.

*Material and Life Science Facility. **Main Ring. ***Relational Database. ****Input Output Controller.

FPAT056 RF Control System Upgrade at CAMD diagnostics, impedance, klystron, resonance 3339
  • V.P. Suller
    CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire
  • M.G. Fedurin, P. Jines, D.J. Launey
    LSU/CAMD, Baton Rouge, Louisiana
  A description is given of the new control system for the RF system of the CAMD light source. The new design being implemented brings all RF signals into the data acquisition system via a modular, custom made, RF detector and renders the amplitude and tune control loops in the VME computer. On line calculations ensure monitoring of proper operation and display the information to the user in an efficient way. In addition, an advanced load impedance monitoring diagnostic has been implemented, being displayed as a Smith Chart, which is based on the system used at the SRS in Daresbury, England.  
FPAT057 A TCL/TK Widget for Display of MEDM Screens background, photon 3393
  • R. Soliday
    ANL, Argonne, Illinois
  Funding: This work is supported by the U.S. Department of Energy, Office of Basic Energy Sciences, under Contract No. W-31-109-ENG-38.

A new Tcl/Tk widget has been created to display MEDM screens inside a Tcl/Tk application. Tcl/Tk parses the MEDM input files and the appropriate widgets are created and linked to the associated process variables. One advantage of this approach is that an X-Windows emulator is not required to view and manipulate the MEDM screen under a Windows operating system. Another benefit is that the MEDM screen can now be tightly integrated into a scripting language to attach higher-level logic to various process variable manipulations. Further details and examples of the new widget will be discussed.

FPAT064 Experience with the EPICS PV Gateway at the APS controls, photon 3621
  • K. Evans, M. Smith
    ANL, Argonne, Illinois
  Funding: Work supported by the U.S. Department of Energy, Office of Basic Energy Sciences, under Contract No. W-31-109-ENG-38.

The EPICS PV Gateway has become a stable, high-performance application that provides access to process variables while minimizing the impact on critical IOCs and implementing additional access security. The additional access security typically prevents write access but is highly configurable. The Advanced Photon Source (APS) currently uses 40 Gateways running on 11 machines to provide access to the machine network from the offices and for the individual experimental teams. These include reverse Gateways that allow administration of all 40 APS Gateways from a single MEDM screen, even though the Gateways are running on separate networks. This administration includes starting, stopping, making and viewing reports, and viewing and editing access security files. There is one Gateway that provides process variable renaming. This paper provides an overview of the Gateways at the APS and describes the procedures that have been set up to use and administer them.

FPAT070 Performance of COTS I/O Modules in an Accelerator Control System power-supply, wiggler, impedance, storage-ring 3822
  • S.M. Hartman
    DU/FEL, Durham, North Carolina
  Funding: This work is supported by U.S. AFOSR MFEL grant F49620-001-0370 and by U.S. Department of Energy grant DE-FG02-01ER41175.

We analyze some recent experiences with commercial off the shelf (COTS) I/O hardware modules, comparing manufacturer specifications with our in-house measurements. Discrepancies between quoted specifications and measured performance under accelerator laboratory conditions have been observed. In some cases, design or manufacturing faults have been found which could have impact on the overall performance of the accelerator.

FPAT090 ExperimentDesigner: A Tcl/Tk Interface for Creating Experiments in EPICS synchrotron, kicker, controls, feedback 4245
  • H. Shang, M. Borland
    ANL, Argonne, Illinois
  Funding: Work supported by the U.S. Department of Energy, Office of Basic Energy Sciences, under Contract No. W-31-109-ENG-38.

ExperimentDesigner is a Tcl/Tk interface that allows users to easily design and run complicated experiments using a convenient graphical user interface (GUI). Features include: process variable monitoring, which pauses the experiment when values are out of range; user-defined initialization, execution, and finalization sequences; support of complex execution chains containing actions such as setting controls, reading values, running external programs, interacting with the user, etc.; collection of output data for convenient postprocessing; saving and loading of experiment configurations; convenient use of SDDS Toolkit programs; and execution of experiments from the command line without a GUI.

FOAA005 Mechanical Vibration Measurements on TTF Cryomodules instrumentation, linac, vacuum, quadrupole 434
  • A. Bosotti, C. Pagani, R. Paparella, P. Pierini, D. Sertore
    INFN/LASA, Segrate (MI)
  • R. De Monte, M. Ferianis
    ELETTRA, Basovizza, Trieste
  • R. Lange
    DESY, Hamburg
  Few of the TTF cryomodules have been equipped with Wire Position Monitors (WPM) for the on line monitoring of cold mass movements during cool-down, warm-up and operation. Each sensor can be used as a detector for mechanical vibrations of the cryostat. A Digital Receiver board is used to sample and analyze with high frequency resolution, the WPM picked up signals, looking to its amplitude modulation in the microphonic frequency range. Here we review and analyze the data and the vibration spectra taken during operation of the TTF cryomodules # 4 and #5.